Shift register and driving method thereof, gate driving circuit

ABSTRACT

Provided are a shift register, a driving method thereof, and a gate driving circuit. The shift register includes an input sub-circuit, a first reset sub-circuit, an output sub-circuit, a pull-down sub-circuit, a pull-down control sub-circuit, and a second reset sub-circuit. The input sub-circuit provides a signal of the first voltage source to the pull-up node and the first node under the control of the signal input terminal; the first reset sub-circuit provides a signal of the second voltage source to the pull-up node and the first node under the control of the reset terminal; the output sub-circuit outputs the signal of the clock signal terminal to the signal output terminal according to the level of the pull-up node.

The present application claims the priority of Chinese PatentApplication No. 202010215034.8 filed to the CNIPA on Mar. 24, 2020,entitled “Shift register and driving method thereof, gate drivingcircuit”, the content of which is incorporated herein by reference.

TECHNICAL FIELD

Embodiments of the present disclosure relate to, but are not limited to,the technical field of display, in particular to a shift register, adriving method thereof and a gate driving circuit.

BACKGROUND

In order to simplify a structure of a display panel, gate lines may bedriven by a Gate Driver on Array (GOA) circuit formed on an arraysubstrate. A gate driving circuit includes multiple cascaded shiftregisters. Each shift register drives a gate line. One shift registermay trigger other shift registers to work when outputting a turn-onsignal. Thus, it is possible to drive all gate lines with several simplecontrol signals.

However, the GOA circuit has a problem that a pull-up node (PU) and apull-down node (PD) compete with each other (that is, influence eachother), which causes poor stability of GOA driving and affects thedisplay quality of the display panel.

SUMMARY

The following is a summary of subject matter described in detail herein.This summary is not intended to limit the protection scope of theclaims.

An embodiment of the disclosure provides a shift register, whichincludes an input sub-circuit, a first reset sub-circuit, an outputsub-circuit, a pull-down sub-circuit, a pull-down control sub-circuitand a second reset sub-circuit. The input sub-circuit is configured toprovide a signal of a first voltage source to a pull-up node and a firstnode respectively under the control of a signal input terminal. Thefirst reset sub-circuit is configured to provide a signal of a secondvoltage source to the pull-up node and the first node respectively underthe control of a reset terminal. The output sub-circuit is configured tooutput a signal of a clock signal terminal to a signal output terminalaccording to a level of the pull-up node. The pull-down controlsub-circuit is configured to control a level of the pull-down nodeaccording to the level of the pull-up node and a signal of a thirdvoltage source. The pull-down sub-circuit is configured to output alevel of a fourth voltage source to the pull-down node according to alevel of the first node, and output the level of the fourth voltagesource to the pull-up node and the signal output terminal according tothe level of the pull-down node. The second reset sub-circuit isconfigured to reset the pull-up node and the signal output terminalunder the control of a total reset terminal.

In an exemplary embodiment, the input sub-circuit includes a firsttransistor and a second transistor. A control electrode of the firsttransistor is connected with the signal input terminal. A firstelectrode of the first transistor is connected with the first voltagesource, and a second electrode of the first transistor is connected withthe pull-up node. A control electrode of the second transistor isconnected with the signal input terminal. A first electrode of thesecond transistor is connected with the first voltage source, and asecond electrode of the second transistor is connected with the firstnode.

In an exemplary embodiment, the first reset sub-circuit includes a thirdtransistor and a fourth transistor. A control electrode of the thirdtransistor is connected with the reset terminal. A first electrode ofthe third transistor is connected with the second voltage source, and asecond electrode of the third transistor is connected with the pull-upnode. A control electrode of the fourth transistor is connected with thereset terminal. A first electrode of the fourth transistor is connectedwith the second voltage source, and a second electrode of the fourthtransistor is connected with the first node.

In an exemplary embodiment, the pull-down sub-circuit includes a fifthtransistor, a six transistor and a seventh transistor. A controlelectrode of the fifth transistor is connected with the first node. Afirst electrode of the fifth transistor is connected with the fourthvoltage source, and a second electrode of the fifth transistor isconnected with the pull-up node. A control electrode of the sixthtransistor is connected with the pull-down node. A first electrode ofthe sixth transistor is connected with the fourth voltage source, and asecond electrode of the sixth transistor is connected with the pull-upnode. A control electrode of the seventh transistor is connected withthe pull-down node. A first electrode of the seventh transistor isconnected with the fourth voltage source. A second electrode of theseventh transistor is connected with the signal output terminal.

In an exemplary embodiment, the pull-down control sub-circuit includesan eighth transistor, a ninth transistor, a tenth transistor and aneleventh transistor. A control electrode and A first electrode of theeighth transistor both are connected with the third voltage source. Asecond electrode of the eighth transistor is connected with the secondnode. A control electrode of the ninth transistor is connected with thesecond node. A first electrode of the ninth transistor is connected withthe third voltage source, and a second electrode of the ninth transistoris connected with the pull-down node. A control electrode of the tenthtransistor is connected with the pull-up node. A first electrode of thetenth transistor is connected with the second node and a secondelectrode of the tenth transistor is connected with the fourth voltagesource. A control electrode of the eleventh transistor is connected withthe pull-up node. A first electrode of the eleventh transistor isconnected with the pull-down node and A second electrode of the eleventhtransistor is connected with the fourth voltage source.

In an exemplary embodiment, the output sub-circuit includes a twelfthtransistor and a capacitor. A control electrode of the twelfthtransistor is connected with the pull-up node. A first electrode of thetwelfth transistor is connected with the clock signal terminal, and asecond electrode of the twelfth transistor is connected with the signaloutput terminal. One terminal of the capacitor is connected with thepull-up node, and the other terminal of the capacitor is connected withthe signal output signal.

In an exemplary embodiment, the second reset sub-circuit includes athirteenth transistor and a fourteenth transistor. A control electrodeof the thirteenth transistor is connected with the total reset terminal.A first electrode of the thirteenth transistor is connected with thefourth voltage source, and the second electrode of the thirteenthtransistor is connected with the signal output terminal. A controlelectrode of the fourteenth transistor is connected with the total resetterminal. A first electrode of the fourteenth transistor is connectedwith the fourth voltage source, and a second electrode of the fourteenthtransistor is connected with the pull-up node.

In an exemplary embodiment, the input sub-circuit include: a firsttransistor and a second transistor. The first reset sub-circuit includesa third transistor and a fourth transistor. The pull-down sub-circuitincludes a fifth transistor, a sixth transistor, and a seventhtransistor. The pull-down control sub-circuit includes an eighthtransistor, a ninth transistor, a tenth transistor and an eleventhtransistor. The output sub-circuit includes a twelfth transistor and acapacitor. The second reset sub-circuit includes a thirteenth transistorand a fourteenth transistor. A control electrode of the first transistoris connected with the signal input terminal. A first electrode of thefirst transistor is connected with the first voltage source, and asecond electrode of the first transistor is connected with the pull-upnode. A control electrode of the second transistor is connected with thesignal input terminal. A first electrode of the second transistor isconnected with the first voltage source, and a second electrode of thesecond transistor is connected with the first node. A control electrodeof the third transistor is connected with the reset terminal. A firstelectrode of the third transistor is connected with the second voltagesource, and a second electrode of the third transistor is connected withthe pull-up node. A control electrode of the fourth transistor isconnected with reset terminal. A first electrode of the fourthtransistor is connected with the second voltage source, and a secondelectrode of the fourth transistor is connected with the first node. Acontrol electrode of the fifth transistor is connected with the firstnode. A first electrode of the fifth transistor is connected with thefourth voltage source, and a second electrode of the fifth transistor isconnected with the pull-down node. A control electrode of the sixthtransistor is connected with the pull-down node. A first electrode ofthe sixth transistor is connected with the fourth voltage source, and asecond electrode of the sixth transistor is connected with the pull-upnode. A control electrode of the seventh transistor is connected withthe pull-down node. A first electrode of the seventh transistor isconnected with the fourth voltage source, and second electrode of theseventh transistor is connected with the signal output signal. A controlelectrode and the first electrode of the eighth transistor both areconnected with the third voltage source, and a second electrode of theeighth transistor is connected with the second node. A control electrodeof the ninth transistor is connected with the second node. A firstelectrode of the ninth transistor is connected with the third voltagesource, and a second electrode of the ninth transistor is connected withpull-down node. A control electrode of the tenth transistor is connectedwith the pull-up node. A first electrode of the tenth transistor isconnected with the second node, and A second electrode of the tenthtransistor is connected with the fourth voltage source. A controlelectrode of the eleventh transistor is connected with the pull-up node.A first electrode of the eleventh transistor is connected with thepull-down node, and a second electrode of the eleventh transistor isconnected with the fourth voltage source. A control electrode of thetwelfth transistor is connected with the pull-up node. A first electrodeof the twelfth transistor is connected with clock signal terminal, and asecond electrode of the twelfth transistor is connected with signaloutput terminal. One terminal of the capacitor is connected with thepull-up node, and the other terminal of the capacitor is connected withthe signal output terminal. A control electrode of the thirteenthtransistor is connected with the total reset terminal. A first electrodeof the thirteenth transistor is connected with the fourth voltagesource, and the second electrode of the thirteenth transistor isconnected with the signal output terminal. A control electrode of thefourteenth transistor is connected with the total reset terminal. Afirst electrode of the fourteenth transistor is connected with thefourth voltage source, and a second electrode of the fourteenthtransistor is connected with the pull-up node.

An embodiment of the present disclosure further provides a gate drivingcircuit including multiple cascaded shift registers as described above.

An embodiment of the present disclosure further provides a drivingmethod for the shift register which is applied to the shift register asdescribed above. During a forward scan, the driving method comprising:providing, by the input sub-circuit, under the control of the signalinput terminal, the signal of the first voltage source to the pull-upnode and the first node; pulling down, by the pull-down controlsub-circuit, according to the level of the pull-up node, the level ofthe pull-down node; outputting, by the pull-down sub-circuit, accordingto the level of the first node, the level of the fourth voltage sourceto the pull-down node; outputting, by the output sub-circuit, accordingto the level of the pull-up node, the signal of the clock signalterminal to the signal output terminal; and providing, by the firstreset sub-circuit, under the control of the reset terminal, the signalof the second voltage source to the pull-up node and the first noderespectively; pulling up, by the pull-down control sub-circuit,according to the signal of the third voltage source, the level of thepull-down node; outputting, by the pull-down sub-circuit, according tothe level of the pull-down node, the level of the fourth voltage sourceto the pull-up node and the signal output terminal.

In an exemplary embodiment, during a reverse scan, the driving methodincludes: providing, by the first reset sub-circuit, under the controlof the reset terminal, the signal of the second voltage source to thepull-up node and the first node respectively; pulling down, by thepull-down control sub-circuit, according to the level of the pull-upnode, the level of the pull-down node; outputting, by the pull-downsub-circuit, according to the level of the first node, the level of thefourth voltage source to the pull-down node; outputting, by the outputsub-circuit, according to the level of the pull-up node, the signal ofthe clock signal terminal to the signal output terminal; and providing,by the first input sub-circuit, under the control of the input terminal,the signal of the first voltage source to the pull-up node and the firstnode respectively; pulling up, by the pull-down control sub-circuit,according to the signal of the third voltage source, the level of thepull-down node; outputting, by the pull-down sub-circuit, according tothe level of the pull-down node, the level of the fourth voltage sourceto the pull-up node and the signal output terminal.

Other aspects will become apparent when the brief description of thedrawings and embodiments of the present disclosure are read andunderstood.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are used to provide an understanding oftechnical schemes of embodiments of the present disclosure, form a partof the specification and explain the technical schemes of the presentdisclosure together with the embodiments of the present disclosure,which do not constitute a limitation to the technical schemes of theembodiments of the present disclosure.

FIG. 1 is a schematic diagram of a structure of a shift registeraccording to an embodiment of the present disclosure;

FIG. 2 is an equivalent circuit diagram of an input sub-circuitaccording to an embodiment of the present disclosure;

FIG. 3 is an equivalent circuit diagram of a first reset sub-circuitaccording to an exemplary embodiment of the present disclosure;

FIG. 4 is an equivalent circuit diagram of a pull-down sub-circuitaccording to an embodiment of the present disclosure;

FIG. 5 is an equivalent circuit diagram of a pull-down controlsub-circuit according to an embodiment of the present disclosure;

FIG. 6 is an equivalent circuit diagram of an output sub-circuitaccording to an embodiment of the present disclosure;

FIG. 7 is an equivalent circuit diagram of a second reset sub-circuitaccording to an embodiment of the present disclosure;

FIG. 8 is an equivalent circuit diagram of a shift register according toan embodiment of the present disclosure;

FIG. 9 is a timing diagram of an operation of a shift register during aforward scan according to an embodiment of the present disclosure;

FIG. 10 is a timing diagram of an operation of a shift register during areverse scan according to an embodiment of the present disclosure;

FIG. 11 is a flowchart of a method driving of shift register accordingto an embodiment of the present disclosure;

FIG. 12 is another flowchart of a driving method of a shift registeraccording to an embodiment of the present disclosure; and

FIG. 13 is a schematic diagram of a structure of a gate driving circuitaccording to an embodiment of the present disclosure.

DETAILED DESCRIPTION

To make the objects, technical schemes and advantages of the presentdisclosure more clear, embodiments of the present disclosure will bedescribed in detail below with reference to the drawings. It should bepointed out that embodiments in the present disclosure and features inthe embodiments may be combined with each other randomly if there is noconflict.

Unless otherwise defined, technical terms or scientific terms used inthe embodiments of the present disclosure shall have the common meaningsas construed by those of ordinary skills in the art to which the presentdisclosure pertains. The words “first”, “second” and the like used inthe embodiments of the present disclosure do not represent any order,quantity or importance, but are merely used to distinguish amongdifferent components. Similar words such as “including” or “comprising”mean that elements or articles preceding the words cover elements orarticles listed after the words and their equivalents, and do notexclude other elements or articles.

Those skilled in the art may understand that transistors used in theembodiments of the present disclosure may be thin film transistors orfield effect transistors or other devices with same characteristics. Thethin film transistor used in the embodiments of the present disclosuremay be an oxide semiconductor transistor. Since a source and a drain ofa transistor used here are symmetrical, the source and the drain may beinterchanged. In the embodiments of the present disclosure, todistinguish the two electrodes, one of two electrodes of the transistorother than the gate is referred to as the first electrode and the otherelectrode is referred to as the second electrode. The first electrodemay be a source or a drain, and the second electrode may be a drain or asource.

An embodiment of the present disclosure provides a shift register. FIG.1 is a schematic diagram of a structure of a shift register according toan embodiment of the present disclosure. As illustrated in FIG. 1 , theshift register according to the embodiment of the present disclosureincludes an input sub-circuit, a first reset sub-circuit, an outputsub-circuit, a pull-down sub-circuit, a pull-down control sub-circuitand a second reset sub-circuit.

The input sub-circuit is connected with a signal input terminal INPUT, afirst voltage source VDS, a pull-up node PU and a first node PD_DCrespectively and is configured to provide a signal of the first voltagesource VDS to the pull-up node PU and the first node PD_DC respectivelyunder the control of the signal input terminal INPUT.

The first reset sub-circuit is connected with a reset terminal RESET, asecond voltage source VSD, the pull-up node PU and the first node PD_DCrespectively and is configured to provide a signal of the second voltagesource VSD to the pull-up node PU and the first node PD_DC under thecontrol of the reset terminal RESET.

The output sub-circuit is connected with a signal output terminalOUTPUT, a clock signal terminal CLK and the pull-up node PU respectivelyand is configured to output a signal of the clock signal terminal CLK tothe signal output terminal OUTPUT according to a level of the pull-upnode PU.

The pull-down control sub-circuit is connected with the pull-up node PU,a pull-down node PD, the third voltage source VDD and the fourth voltagesource VSS and is configured to control a level of the pull-down node PDaccording to the level of the pull-up node PU and a signal of the thirdvoltage source VDD.

The pull-down sub-circuit is connected to the pull-up node PU, thesignal output terminal OUTPUT, the pull-down node PD, the first nodePD_DC and the fourth voltage source VSS and is configured to output thelevel of the fourth voltage source VSS to the pull-down node PDaccording to a level of the first node PD_DC, and to output the level ofthe fourth voltage source VSS to the pull-up node PU and the signaloutput terminal OUTPUT according to the level of the pull-down node PD.

The second reset sub-circuit is connected with a total reset terminalTRST, the fourth voltage source VSS, the pull-up node PU and the signaloutput terminal OUTPUT and is configured to reset the pull-up node PUand the signal output terminal OUTPUT under the control of the totalreset terminal TRST.

In the shift register of the embodiment of the present disclosure, theinput sub-circuit provides the signal of the first voltage source VDS tothe first node PD_DC under the control of the signal input terminalINPUT. The first reset sub-circuit provides the signal of the secondvoltage source VSD to the first node PD_DC under the control of thereset terminal RESET. The pull-down sub-circuit outputs the level of thefourth voltage source VSS to the pull-down node PD according to thelevel of the first node PD_DC. Therefore, the problem that the pull-upnode PU and the pull-down node PD compete with each other during dualscan is well solved, which improves the stability of GOA driving and thedisplay quality of the display panel.

In the embodiment of the present disclosure, the total reset terminalTRST has two functions. The first function is to reset a last row ofshift register units. There are no subsequent units supplying resetsignals to the last row of shift register units and therefore, a totalreset terminal TRST is provided to reset the last row. The secondfunction is to reset all the rows of shift register units simultaneouslywhile resetting the last row of shift register units to improve thestability of the circuit. The total reset signal is equivalent to aninitialization signal of each frame. That is, the total reset terminalTRST pulls down the signal output terminal OUTPUT and pull-up node PU inall shift register units at the end of each frame. That is,initialization is performed for once each frame, which can improve thereliability of the shift register. The total reset terminal TRST is at ahigh level only when the last row of shift register units is reset. Thereset terminal RESET is used for a next shift register unit to reset aprevious shift register unit.

In an exemplary embodiment, FIG. 2 is an equivalent circuit diagram ofan input sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 2 , the first input sub-circuitaccording to the embodiment of the present disclosure includes a firsttransistor M1 and a second transistor M2.

A control electrode of the first transistor M1 is connected with thesignal input terminal INPUT. A first electrode of the first transistorM1 is connected with the first voltage source VDS, and a secondelectrode of the first transistor M1 is connected with the pull-up nodePU. A control electrode of the second transistor M2 is connected withthe signal input terminal INPUT. A first electrode of the secondtransistor M2 is connected with the first voltage source VDS, and asecond electrode of the second transistor M2 is connected with the firstnode PD_DC.

FIG. 2 illustrates an exemplary structure of the input sub-circuit.Those skilled in the art should easily appreciate that implementationsof the input sub-circuit are not limited to this as long as theirfunctions can be achieved.

In an exemplary embodiment, FIG. 3 is an equivalent circuit diagram of afirst reset sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 3 , the first reset sub-circuitaccording to the embodiment of the present disclosure includes a thirdtransistor M3 and a fourth transistor M4.

A control electrode of the third transistor M3 is connected with a resetterminal RESET. A first electrode of the third transistor M3 isconnected with a second voltage source VSD, and a second electrode ofthe third transistor M3 is connected with a pull-up node PU. A controlelectrode of the fourth transistor M4 is connected to the reset terminalRESET. A first electrode of the fourth transistor M4 is connected to thesecond voltage source VSD, and a second electrode of the fourthtransistor M4 is connected to a first node PD_DC.

FIG. 3 illustrates an exemplary structure of the first resetsub-circuit. Those skilled in the art should easily appreciate thatimplementations of the input circuit are not limited to this as long astheir respective functions can be achieved.

In an exemplary embodiment, FIG. 4 is an equivalent circuit diagram of apull-down sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 4 , the pull-down sub-circuitaccording to the embodiment of the present disclosure includes a fifthcapacitor M5, a sixth transistor M6 and a seventh transistor M7.

A control electrode of the fifth transistor M5 is connected with a firstnode PD_DC. A first electrode of the fifth transistor M5 is connectedwith a fourth voltage source VSS, and a second electrode of the fifthtransistor M5 is connected with a pull-down node PD. A control electrodeof the sixth transistor M6 is connected with the pull-down node PD. Afirst electrode of the sixth transistor M6 is connected with the fourthvoltage source VSS, and a second electrode of the sixth transistor M6 isconnected with a pull-up node PU. A control electrode of the seventhtransistor M7 is connected with the pull-down node PD. A first electrodeof the seventh transistor M7 is connected with the fourth voltage sourceVSS, and a second electrode of the seventh transistor M7 is connectedwith a signal output terminal OUTPUT.

FIG. 4 illustrates an exemplary structure of the pull-down sub-circuit.Those skilled in the art should easily appreciate that implementationsof the pull-down sub-circuit are not limited to this as long as theirrespective functions can be achieved.

In an exemplary embodiment, FIG. 5 is an equivalent circuit diagram of apull-down control sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 5 , the pull-down control sub-circuitaccording to the embodiment of the present disclosure includes an eighthtransistor M8, a ninth transistor M9, a tenth transistor M10 and aneleventh transistor M11.

A control electrode and a first electrode of the eighth transistor M8both are connected with a third voltage source VDD. A second electrodeof the eighth transistor M8 is connected with a second node PD_CN. Acontrol electrode of the ninth transistor M9 is connected with thesecond node PD_CN. A first electrode of the ninth transistor M9 isconnected with a third voltage source VDD, and a second electrode of theninth transistor M9 is connected with a pull-down node PD. A controlelectrode of the tenth transistor M10 is connected with the pull-downnode PD. A first electrode of the tenth transistor M10 is connected withthe second node PD_CN and A second electrode of the tenth transistor M10is connected with the fourth voltage source VSS. A control electrode ofthe eleventh transistor M11 is connected with a pull-up node PU. A firstelectrode of the eleventh transistor M11 is connected with the pull-downnode PD and a second electrode of the eleventh transistor M11 isconnected with the fourth voltage source VSS.

FIG. 5 illustrates an exemplary structure of the pull-down controlsub-circuit. Those skilled in the art should easily appreciate thatimplementations of the above various sub-circuits are not limited tothis as long as their respective functions can be achieved.

In an exemplary embodiment, FIG. 6 is an equivalent circuit diagram ofan output sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 6 , the output sub-circuit accordingto the embodiment of the present disclosure includes a twelfthtransistor M12 and a capacitor C.

A control electrode of the twelfth transistor M12 is connected with apull-up node PU. A first electrode of the twelfth transistor M12 isconnected with a clock signal terminal CLK, and a second electrode ofthe twelfth transistor M12 is connected with a signal output terminalOUTPUT. One terminal of the capacitor C is connected with a pull-up nodePU, and the other terminal of the capacitor C is connected with thesignal output terminal OUTPUT.

FIG. 6 illustrates an exemplary structure of the output sub-circuit.Those skilled in the art should easily appreciate that implementationsof the output sub-circuit are not limited to this as long as theirrespective functions can be achieved.

In an exemplary embodiment, FIG. 7 is an equivalent circuit diagram of asecond reset sub-circuit according to an embodiment of the presentdisclosure. As illustrated in FIG. 7 , the second reset sub-circuitaccording to the embodiment of the present disclosure includes athirteenth transistor M13 and a fourteenth transistor M14.

A control electrode of the thirteenth transistor M13 is connected with atotal reset terminal TRST. A first electrode of the thirteenthtransistor M13 is connected with a fourth voltage source VSS, and asecond electrode of the thirteenth transistor M13 is connected with asignal output terminal OUTPUT. A control electrode of the fourteenthtransistor M14 is connected with the total reset terminal TRST. A firstelectrode of the fourteenth transistor M14 is connected with the fourthvoltage source VSS, and a second electrode of the fourteenth transistorM14 is connected with a pull-up node PU.

FIG. 7 illustrates an exemplary structure of the second resetsub-circuit. Those skilled in the art should easily appreciate thatimplementations of the second reset sub-circuit are not limited to thisas long as their respective functions can be achieved.

FIG. 8 is an equivalent circuit diagram of a shift register according toan embodiment of the present disclosure. As illustrated in FIG. 8 , inthe shift register provided by the embodiment of the present disclosure,an input sub-circuit includes: a first transistor M1 and a secondtransistor M2. A first reset sub-circuit includes a third transistor M3and a fourth transistor M4. A pull-down sub-circuit includes a fifthtransistor M5, a sixth transistor M6, and a seventh transistor M7. Apull-down control sub-circuit includes an eighth transistor M8, a ninthtransistor M9, a tenth transistor M10 and an eleventh transistor M11. Aoutput sub-circuit includes a twelfth transistor M12 and a capacitor C.A second reset sub-circuit includes a thirteenth transistor M13 and afourteenth transistor M14.

A control electrode of the first transistor M1 is connected with asignal input terminal INPUT. A first electrode of the first transistorM1 is connected with a first voltage source VDS, and a second electrodeof the first transistor M1 is connected with a pull-up node PU. Acontrol electrode of the second transistor M2 is connected with thesignal input terminal INPUT. A first electrode of the second transistorM2 is connected with the first voltage source VDS, and a secondelectrode of the second transistor M2 is connected with a first nodePD_DC. A control electrode of the third transistor M3 is connected witha reset terminal RESET. A first electrode of the third transistor M3 isconnected with the second voltage source VSD, and a second electrode ofthe third transistor M3 is connected with the pull-up node PU. A controlelectrode of the fourth transistor M4 is connected with reset terminalRESET. A first electrode of the fourth transistor M4 is connected withthe second voltage source VSD, and a second electrode of the fourthtransistor M4 is connected with the first node PD_DC. A controlelectrode of the fifth transistor M5 is connected with the first nodePD_DC. A first electrode of the fifth transistor M5 is connected with afourth voltage source VSS, and a second electrode of the fifthtransistor M5 is connected with a pull-down node PD. A control electrodeof the sixth transistor M6 is connected with the pull-down node PD. Afirst electrode of the sixth transistor M6 is connected with the fourthvoltage source VSS, and a second electrode of the sixth transistor M6 isconnected with pull-up node PU. A control electrode of the seventhtransistor M7 is connected with the pull-down node PD. A first electrodeof the seventh transistor M7 is connected with the fourth voltage sourceVSS, and a second electrode of the seventh transistor M7 is connectedwith the signal output terminal OUTPUT. A control electrode and a firstelectrode of the eighth transistor M8 both are connected with the thirdvoltage source VDD, and a second electrode of the eighth transistor M8is connected with the second node PD_CN. A control electrode of theninth transistor M9 is connected with the second node PD_CN. A firstelectrode of the ninth transistor M9 is connected with the third voltagesource VDD and a second electrode of the ninth transistor M9 isconnected with pull-down node PD. A control electrode of the tenthtransistor M10 is connected with the pull-up node PU. A first electrodeof the tenth transistor M10 is connected with the second node PD_CN, anda second electrode of the tenth transistor M10 is connected with thefourth voltage source VSS. A control electrode of the eleventhtransistor M11 is connected with the pull-up node PU. A first electrodeof the eleventh transistor M11 is connected with the pull-down node PD,and a second electrode of the eleventh transistor M11 is connected withthe fourth voltage source VSS. A control electrode of the twelfthtransistor M12 is connected with the pull-up node PU. A first electrodeof the twelfth transistor M12 is connected with clock signal terminalCLK, and a second electrode of the twelfth transistor M2 is connectedwith signal output terminal OUTPUT. One terminal of the capacitor C isconnected with the pull-up node PU, and the other terminal of thecapacitor C is connected with the signal output terminal OUTPUT. Acontrol electrode of the thirteenth transistor M13 is connected with atotal reset terminal TRST. A first electrode of the thirteenthtransistor M13 is connected with the fourth voltage source VSS, and asecond electrode of the thirteenth transistor M13 is connected with thesignal output terminal OUTPUT. A control electrode of the fourteenthtransistor M14 is connected with the total reset terminal TRST. A firstelectrode of the fourteenth transistor M14 is connected with the fourthvoltage source VSS, and the second electrode of the fourteenthtransistor M14 is connected with the pull-up node PU.

FIG. 8 illustrates the exemplary structure of the input sub-circuit, thefirst reset sub-circuit, the pull-down sub-circuit, the pull-downcontrol sub-circuit, the output sub-circuit, and the second resetsub-circuit. Those skilled in the art should easily appreciate thatimplementations of the above various sub-circuits are not limited tothis as long as their respective functions can be achieved.

In this embodiment, the transistors M1 to M14 may all be N-type thinfilm transistors or P-type thin film transistors, such that processflows can be unified and process manufacturing procedures can bereduced, contributing to the improvement of the yield of qualifiedproducts. As low-temperature polysilicon thin film transistor has asmall leakage current, all transistors of the embodiment of the presentdisclosure may be low-temperature polysilicon thin film transistors witha bottom gate structure or a top gate structure, as long as a switchfunction can be achieved.

The capacitor C may be a liquid crystal capacitor including a pixelelectrode and a common electrode, or an equivalent capacitor containinga storage capacitor and the liquid crystal capacitor including the pixelelectrode and the common electrode, which is not limited in the presentembodiment.

Technical schemes of the embodiments of the present disclosure will befurther illustrated below by an operation process of a shift register.The following describes the working process of a first stage shiftregister as an example.

Taking that transistors M1-M14 in a shift register according to anembodiment of the present disclosure are N-type thin film transistors asan example. FIG. 9 is a timing diagram of an operation of a shiftregister during a forward scan according to an embodiment of the presentdisclosure; FIG. 10 is a timing diagram of an operation of a shiftregister during a reverse scan according to an embodiment of the presentdisclosure. As illustrated in FIG. 8 , FIG. 9 and FIG. 10 , the shiftregister according to the embodiment of the present disclosure includes14 transistor units (M1-M14), one capacitor unit (C), five inputterminals (INPUT RESET, CLK and TRST), one output terminal (OUTPUT) andfour voltage sources (VDS, VSD, VSS and VDD). The third voltage sourceVDD continuously provides high-potential signals, and the fourth powerterminal VSS continuously provides low-potential signals.

As illustrated in FIG. 9 , the forward scan timing can be divided intosix phases, t1 to t6. During the forward scan, the first voltage sourceVDS inputs a high-potential signal VGH, and the second voltage sourceVSD inputs a low-potential signal VGL.

At phase t1, a high-potential signal is input by the signal inputterminal INPUT of the shift register G_n. Since an input signal via thesignal input terminal INPUT of the shift register G_n is an outputsignal of the signal output terminal OUTPUT of a previous-stage shiftregister G_n−1, it can be said that a high-potential signal from thesignal output terminal OUTPUT of the previous-stage shift register G_n−1is input to the signal input terminal INPUT of the shift register G_n.Thus, the first transistor M1 and the second transistor M2 are turnedon, and the first voltage source VDS charges the capacitor C via thefirst transistor, so that the potential of the pull-up node PU to bepulled up to a high potential. The tenth transistor M10, the eleventhtransistor M11 and the twelfth transistor M12 are turned on are underthe driving of the high potential of the pull-up node PU. The first nodePD_DC potential is pulled up as the second transistor M2 is turned on.The fifth transistor M5 is turned on under the driving of the highpotential of the first node PD_DC to discharge to the pull-down node PD.The sixth transistor M6 and the seventh transistor M7 are turned off toprevent the sixth transistor M6 from discharging to the pull-up node PU,that is, to prevent the competition between the pull-down node PD andthe pull-up node PU. A low-potential signal is input via the clocksignal terminal CLK, and the low-potential signal input by the clocksignal terminal CLK is transmitted to the signal output terminal OUTPUTvia the twelfth transistor M12.

At phase t2, a low-potential signal is input by the signal inputterminal INPUT of the shift register G_n, and the first transistor M1 isturned off. However, since the capacitor C has already stored thehigh-potential signal input by the first voltage source VDS at phase t1,the potential of the pull-up node PU is still at a high potential. Then,as a high-potential signal is input via the clock signal terminal CLK,the voltage of the pull-up node PU is amplified due to bootstrap effect,that is, the potential of the terminal of the capacitor C connected withthe pull-up node PU continues to rise on the basis of that at phase t1,and the twelfth transistor M12 maintains a turn-on state. Therefore, thehigh-potential signal input by the clock signal terminal CLK istransmitted to the signal output terminal OUTPUT via the twelfthtransistor M12. The potential of the pull-down node PD maintains at alow potential as that at phase t1 and therefore, the sixth transistor M6and the seventh transistor M7 maintains a turn-off state, which preventsthe output signal of the signal output terminal OUTPUT from being pulleddown to the potential of VGL.

At phase t3, a period during a low-potential signal is input by thesignal input terminal INPUT of shift register G_n, and a low-potentialsignal is input by the clock signal terminal CLK may be a touch period.during this period, the pull-up node PU is at a high level and the tenthtransistor M10 and the eleventh transistor M11 maintains turn-on state,so that both the second node PD_CN and the pull-down node PD are at alow level, and the seventh transistor M7 is turned off Although thetwelfth transistor M12 is turned on, the output signal of the signaloutput terminal OUTPUT is at a low level as the clock signal CLKmaintains a low level.

At phase t4, a high-potential signal is input by the reset terminalRESET of the shift register G_n and a low-potential signal is input bythe clock signal terminal CLK. The high-potential signal input by thereset terminal RESET is a signal output by the signal output terminalOUTPUT of the next-stage shift register G_n+1. The third transistor M3and the fourth transistor M4 are turned on. Therefore, the potential ofthe pull-up node PU connected to one terminal of the third transistor M3is pulled down to the low potential of the second voltage source VSD,and then the tenth transistor M10 and the eleventh transistor M11 areturned off while the eighth transistor M8 and the ninth transistor M9are turned on. The potential of the first node PD_DC is pulled up, andthe potential of the first node PD_DC connected with one terminal of thefourth transistor M4 is pulled down to the low potential of the secondvoltage source VSD, and the fifth transistor M5 is turned off. At thistime, the pull-down node PD is only connected with the second electrodeof the ninth transistor M9 while the first electrode of the ninthtransistor M9 is connected with the third voltage source VDD and thus,the potential of the pull-down node PD becomes a high potential.

Since a gate of the sixth transistor M6 and a gate of the seventhtransistor M7 both are connected with the pull-down node PD, both thesixth transistor M6 and the seventh transistor M7 are turned on when thepotential of the pull-down node PD becomes a high potential. As thesixth transistor M6 is turned on, the pull-up node PU is pulled down toa low potential VGL. The gate of the twelfth transistor M12 is connectedwith the pull-up node PU and thus, the twelfth transistor M12 is turnedoff after the potential of the pull-up node PU is lowered to thepotential of VGL. As the seventh transistor M7 is turned on, the signaloutput terminal OUTPUT is connected with the fourth voltage source VSS,and the potential of the signal output terminal OUTPUT is reset to a lowpotential.

At phase t5, a high-potential signal is input by the clock signalterminal CLK. Since the pull-down node PD is at a high potential whilethe pull-up node PU connected with a gate of the twelfth transistor M12is still at a low potential, the high-potential signal input by theclock signal terminal CLK will not be transmitted to the signal outputterminal OUTPUT as the twelfth transistor M12 maintains a turn-off stateas it is at phase t4. Since the seventh transistor M7 is still turnedon, the signal output terminal OUTPUT is still connected with the fourthvoltage source VSS, the signal output terminal OUTPUT continues tooutput the low-potential signal VGL of the phase t4, eliminating thecoupling noise generated by the high-potential signal of clock signalCLK at signal output terminal OUTPUT, which ensures the stability of thesignal output by signal output terminal OUTPUT.

At phase t6, a low-potential signal is input by the clock signalterminal CLK. Since the pull-down node PD is at a high potential whilethe pull-up node PU connected with a gate of the twelfth transistor M12is still at a low potential, the twelfth transistor M12 maintains theturn-off state as it is at phase t4. Since the seventh transistor M7 isstill turned on, the signal output terminal OUTPUT is still connectedwith the fourth voltage source VSS, the signal output terminal OUTPUTcontinues to output the low-potential signal VGL of the phase t4. Afterthe above, phase t5 and phase t6 are repeated in sequence until theshift register according to the embodiment of the present disclosurereceives the high-potential signal from the signal input terminal INPUT,and then phase t1 is re-executed.

When the last row of shift register units are reset, a high-potentialsignal is input by the total reset terminal TRST of the shift registerG_n, and the thirteenth transistor M13 and the fourteenth transistor M14are turned on, to pull down the potentials of the signal output terminalOUTPUT and the pull-up node PU in all shift register units in the shiftregister, and to reset the shift register units in all rows, whichimproves the stability of the circuit.

As illustrated in FIG. 10 , the reverse scan timing can be divided intosix phases, T1 to T6. During the reverse scan, the first voltage sourceVDS inputs a low-potential signal while the second voltage source VSDinputs a high-potential signal, and the reset terminal RESET isequivalent to the signal input terminal INPUT during the forward scan,the signal input terminal INPUT is equivalent to the reset terminalRESET during the forward scan.

At phase T1, a high-potential signal is input by the reset terminalRESET. Since the input signal via the reset terminal RESET of the shiftregister G_n is the output signal of the signal output terminal OUTPUTof the next-stage shift register G_n+1, it can be said that thehigh-potential signal of the signal output terminal OUTPUT of thenext-stage shift register G_n+1 is input to the reset terminal RESET ofthe shift register G_n. Thus, the third transistor M3 and the fourthtransistor M4 is turned on, and the second voltage source VSD chargesthe capacitor C via the third transistor M3, so that the potential ofthe pull-up node PU is pulled up to a high potential, and the tenthtransistor M10, the eleventh transistor M11 and the twelfth transistorM12 are turned on under the driving of the high potential of the pull-upnode PU. The first node PD_DC potential is pulled up as the fourthtransistor M4 is turned on. The fifth transistor M5 is turned on underthe driving of the high potential of the first node PD_DC to dischargeto the pull-down node PD. The sixth transistor M6 and the seventhtransistor M7 are turned off to prevent the sixth transistor M6 fromdischarging to the pull-up node PU, that is, to prevent the competitionbetween the pull-down node PD and the pull-up node PU. A low-potentialsignal is input by the clock signal terminal CLK and the low-potentialsignal is transmitted to the signal output terminal OUTPUT via thetwelfth transistor M12.

At phase T2, a low-potential signal is input by the reset terminal RESETof the shift register G_n, and the third transistor M3 is turned off.However, since the capacitor C has already stored the high-potentialsignal input by the second voltage source VSD in phase T1, the potentialof the pull-up node PU is still a high potential. Then, as ahigh-potential signal is input by the clock signal terminal CLK, thevoltage of the pull-up node PU is amplified due to bootstrap effect,that is, the potential of the terminal of the capacitor C connected withthe pull-up node PU continues to rise on the basis of that at phase T1,and the twelfth transistor M12 maintains the turn-on state. Therefore,the high-potential signal input by the clock signal terminal CLK istransmitted to the signal output terminal OUTPUT via the twelfthtransistor M12. The potential of the pull-down node PD maintains at alow potential as that at phase T1 and therefore, the sixth transistor M6and the seventh transistor M7 maintains the turned-off state, whichprevents the output signal of the signal output terminal OUTPUT frombeing pulled down to the potential of VGL.

At phase T3, a period during a low-potential signal is input by thereset terminal RESET of shift register G_n and the a low-potentialsignal is input by the clock signal terminal CLK may be a touch period.during this period, the pull-up node PU is at a high level and the tenthtransistor M10 and the eleventh transistor M11 maintains the turn-onstate, so that the second node PD_CN and the pull-down node PD both areat a low level. The seventh transistor M7 is turned off. Although thetwelfth transistor M12 is turned on, the output signal of the signaloutput terminal OUTPUT is at a low level as the clock signal CLKmaintains at a low level.

At phase T4, a high-potential signal is put by the signal input terminalINPUT of the shift register G_n and a low-potential signal is input bythe clock signal terminal CLK. The high-potential signal input by thesignal input terminal INPUT is a signal output by the signal outputterminal OUTPUT of the pervious-stage shift register G_n−1. The firsttransistor M1 and the second transistor M2 are turned on. Therefore, thepotential of the pull-up node PU connected to one terminal of the firsttransistor M1 is pulled down to the low potential of the first voltagesource VDS, and then the tenth transistor M10 and the eleventhtransistor M11 are turned off while the eighth transistor M8 and theninth transistor M9 are turned on. The potential of the first node PD_DCconnected with one terminal of the second transistor M2 is pulled downto the low potential of the first voltage source VDS. The pull-down nodePD is only connected with the second electrode of the ninth transistorM9 while the first electrode of the ninth transistor M9 is connectedwith the third voltage source VDD and thus, the potential of thepull-down node PD becomes a high potential. Since the gate of the sixthtransistor M6 and the gate of the seventh transistor M7 both areconnected with the pull-down node PD, both the sixth transistor M6 andthe seventh transistor M7 are turned on when the potential of thepull-down node PD becomes a high potential. As the sixth transistor M6is turned on, the pull-up node PU is pulled down to a low potential VGL.The gate of the twelfth transistor M12 is connected with the pull-upnode PU and thus, the twelfth transistor M12 is turned off after thepotential of the pull-up node PU is lowered to the low potential offirst voltage source VDS. As the seventh transistor M7 is turned on, thesignal output terminal OUTPUT is connected with the fourth voltagesource VSS, and the potential of the signal output terminal OUTPUT isreset to a low potential.

At phase T5, a high-potential signal is input by the clock signalterminal CLK. Since the pull-down node PD is at a high potential whilethe pull-up node PU connected with a gate of the twelfth transistor M12is still at a low potential, the high-potential signal input by theclock signal terminal CLK will not be transmitted to the signal outputterminal OUTPUT as the twelfth transistor M12 maintains the turn-offstate as it is at phase T4. Since the seventh transistor M7 is stillturned on, the signal output terminal OUTPUT is still connected with thefourth voltage source VSS, the signal output terminal OUTPUT continuesto output the low-potential signal of the phase t4, eliminating thecoupling noise generated by the high-potential signal of clock signalCLK at signal output terminal OUTPUT, which ensures the stability of thesignal output by signal output terminal OUTPUT.

At phase T6, a low-potential signal is input by the clock signalterminal CLK. Since the pull-down node PD is at a high potential whilethe pull-up node PU connected with a gate of the twelfth transistor M12is still at a low potential, the twelfth transistor M12 still maintainsthe turn-off state as it is at phase T4. Since the seventh transistor M7is still turned on, the signal output terminal OUTPUT is still connectedwith the fourth voltage source VSS, the signal output terminal OUTPUTcontinues to output the low-potential signal of the phase T4. After theabove, phase T5 and phase T6 are repeated in sequence until the shiftregister according to the embodiment of the present disclosure receivesthe high-potential signal from the reset terminal RESET, and then phaseT1 is re-executed.

When the last row of shift register units are reset, a high-potentialsignal is input by the total reset terminal TRST of the shift registerG_n, and the thirteenth transistor M13 and the fourteenth transistor M14are turned on, to pull down the potentials of the signal output terminalOUTPUT and the pull-up node PU in all shift register units in the shiftregister, and to reset the shift register units in all rows, whichimproves the stability of the circuit.

Transistors of the shift register are connected in the same way asduring the forward scan and the reverse scan, except that the outputlevel signals of the first voltage source VDS and that of the secondvoltage source VSD are different. For example, when the shift registerperforms the forward scan, the first voltage source VDS outputs ahigh-level signal while the second voltage source VSD outputs alow-level signal. When the shift register performs the reverse scan, thefirst voltage source VDS outputs a low-level signal while the secondvoltage source VSD outputs a high-level signal.

In an embodiment of the present disclosure, the shift register includesa first voltage source VDS, a second voltage source VSD, a third voltagesource VDD and a fourth voltage source VSS. The output level signals ofeach voltage source are different during the forward scan and thereverse scan, for example:

The first voltage source VDS outputs a high-level signal when the shiftregister performs the forward scan. The first voltage source VDS outputsa low-level signal when the shift register performs the reverse scan.

The second voltage source VSD outputs a low-level signal when the shiftregister performs the forward scan. The second voltage source VSDoutputs a high-level signal when the shift register performs the reversescan.

The third voltage source VDD outputs a high-level signal VGH when theshift register performs the forward scan and the reverse scan.

The third voltage source VSS outputs a low-level signal VGL when theshift register performs the forward scan and the reverse scan.

In an embodiment of the present disclosure, the input sub-circuitprovides the signal of the first voltage source VDS to the first nodePD_DC under the control of the signal input terminal INPUT. The firstreset sub-circuit provides the signal of the second voltage source VSDto the first node PD_DC under the control of the reset terminal RESET.The pull-down sub-circuit outputs the level of the fourth voltage sourceVSS to the pull-down node PD according to the level of the first nodePD_DC. Therefore, the problem that the pull-up node PU and the pull-downnode PD compete with each other during a dual scan is well solved, whichimproves the stability of GOA driving and the display quality of thedisplay panel.

Some embodiments of the present disclosure also provide a driving methodof a shift register applied to the shift register according to theprevious embodiments. The shift register includes an input sub-circuit,a first reset sub-circuit, a pull-down sub-circuit, a pull-down controlsub-circuit, an output sub-circuit and a second reset sub-circuit, aswell as a signal input terminal, a clock signal terminal, a resetterminal, a first voltage source, a second voltage source, a thirdvoltage source, a fourth voltage source and a signal output terminal.FIG. 11 is a flowchart of a driving method of a shift register during aforward scan according to an embodiment of the present disclosure. Thedriving method includes the following steps:

Step 100: The input sub-circuit provides the signal of the first voltagesource to the pull-up node and the first node under the control of thesignal input terminal. The pull-down control sub-circuit pulls down thelevel of the pull-down node according to the level of the pull-up node.The pull-down sub-circuit outputs the level of the fourth voltage sourceto the pull-down node according to the level of the first node.

In an exemplary embodiment, the first voltage source outputs ahigh-level signal when the shift register performs the forward scan, andthe fourth voltage source outputs a low-level signal when the shiftregister performs both the forward and the reverse scan. In this step,the potential of the pull-down node is pulled down to prevent thepotential of the pull-down node from affecting the potential of thepull-up node.

Step 200: The output sub-circuit outputs the signal from the clocksignal terminal to the signal output terminal according to the level ofthe pull-up node.

In an exemplary embodiment, the input signal from the clock signalterminal is a pulse signal. In this step, the input signal from theclock signal terminal is at a high level, and the output signal of thesignal output terminal is at a high level.

Step 300: The first reset sub-circuit provides the signal of the secondvoltage source to the pull-up node and the first node respectively underthe control of the reset terminal. The pull-down control sub-circuitpulls up the level of the pull-down node according to the signal of thethird voltage source. The pull-down sub-circuit outputs the level of thefourth voltage source to the pull-up node and the signal output terminalaccording to the level of the pull-down node.

In an exemplary embodiment, the second voltage source outputs alow-level signal when the shift register performs the forward scan, andthe third voltage source outputs a high-level signal when the shiftregister performs both the forward scan and the reverse scan. Thepull-down sub-circuit pulls down the levels of the pull-up node and thesignal output terminal to the low-level signal of the fourth voltagesource to avoid noise.

In an exemplary embodiment, the driving method further includes: whenthe last row of shift register units are reset, the second resetsub-circuit resets the signal output terminals and pull-up nodes of allshift register units under the control of the total reset terminal.

FIG. 12 is a flowchart of a driving method of shift register during areverse scan according to an embodiment of the present disclosure.During the reverse scan, the driving method includes the followingsteps:

Step 400: The first reset sub-circuit provides the signal of the secondvoltage source to the pull-up node and the first node respectively underthe control of the reset terminal. The pull-down control sub-circuitpulls down the level of the pull-down node according to the level of thepull-up node. The pull-down sub-circuit outputs the level of the fourthvoltage source to the pull-down node according to the level of the firstnode.

In an exemplary embodiment, the second voltage source outputs ahigh-level signal when the shift register performs the reverse scan, andthe fourth voltage source outputs a low-level signal when the shiftregister performs both the forward scan and the reverse scan. In thisstep, the potential of the pull-down node is pulled down to prevent thepotential of the pull-down node from affecting the potential of thepull-up node.

Step 500: The output sub-circuit outputs the signal from the clocksignal terminal to the signal output terminal according to the level ofthe pull-up node.

In an exemplary embodiment, the input signal from the clock signalterminal is a pulse signal. In this step, the input signal from theclock signal terminal is at a high level, and the output signal of thesignal output terminal is at a high level.

Step 600: The input sub-circuit provides the signal of the first voltagesource to the pull-up node and the first node under the control of thesignal input terminal. The pull-down control sub-circuit pulls up thelevel of the pull-down node according to the signal of the third voltagesource. The pull-down sub-circuit outputs the level of the fourthvoltage source to the pull-up node and the signal output terminalaccording to the level of the pull-down node.

In an exemplary embodiment, the first voltage source outputs a low-levelsignal when the shift register performs the reverse scan, and the thirdvoltage source outputs a high-level signal when the shift registerperforms both the forward scan and the reverse scan. The pull-downsub-circuit pulls down the levels of the pull-up node and the signaloutput terminal to the low-level signal of the fourth voltage source toavoid noise.

In an exemplary embodiment, the driving method further includes: whenthe last row of shift register units are reset, the second resetsub-circuit resets the signal output terminals and pull-up nodes of allshift register units under the control of the total reset terminal.

In the driving method of the shift register according to an embodimentof the present disclosure, the input sub-circuit provides the signal ofthe first voltage source to the first node under the control of thesignal input terminal. The first reset sub-circuit provides the signalof the second voltage source to the first node under the control of thereset terminal. The pull-down sub-circuit outputs the level of thefourth voltage source to the pull-down node according to the level ofthe first node. Therefore, the problem that the pull-up node and thepull-down node compete with each other during dual scan is well solved,which improves the stability of GOA driving and the display quality ofthe display panel.

An embodiment of the present disclosure further provides a gate drivingcircuit. FIG. 13 is a schematic diagram of a structure of a gate drivingcircuit according to an embodiment of the present disclosure. Asillustrated in FIG. 13 , the gate driving circuit includes a pluralityof cascaded shift registers, a signal output terminal of each shiftregister is connected with a gate line for driving the gate line.

In an exemplary embodiment, for example, when each shift registerperforms a forward scan, the first voltage source outputs a high-levelsignal while the second voltage source outputs a low-level signal, and,except that of a last stage shift register, the signal output terminalof each shift register is also connected with the signal input terminalof the next-stage shift register. A signal input terminal of afirst-stage shift register needs to be connected with a separate drivesignal. Meanwhile, the signal output terminal of each shift register,except that of the first-stage shift register, is further connected witha reset terminal of a previous-stage shift register. A reset terminal ofthe last-stage shift register is connected with a separate drivingsignal.

In the gate driving circuit, the levels of the clock signal terminals ofthe shift registers of the adjacent two stages are opposite. Forexample, the clock signal terminal of the shift register SR2 inputs ahigh-potential signal, while the clock signal terminal of the shiftregister SR1 and that of the shift register SR3 inputs a low-levelsignal. Each shift register, except the redundant register, converts theinput clock signal into a turn-on or turn-off signal and outputs thesignal from its signal output terminal to a corresponding gate line. Forexample, the shift register SR1 converts the signal received from itsclock signal terminal into a turn-on or turn-off signal and outputs thesignal from the its signal output terminal to a corresponding gate lineGL1, and the shift register SRn converts the signal received from itsclock signal terminal to a turn-on or turn-off signal and outputs thesignal from its the signal output terminal to a corresponding gate lineGLn.

The shift register is the shift register according to any one of theaforementioned embodiments and has similar implementation principle andimplementation effect which will not be described in detail here again.

The accompanying drawings of the embodiments of the present disclosureonly involve structures involved in the embodiments of the presentdisclosure, and other structures will be apparent with reference togeneral designs.

The embodiments of the present disclosure (that is, features in theembodiments) may be combined with each other to obtain new embodimentswhere there is no conflict.

Although the embodiments disclosed in the present disclosure are asdescribed above, the embodiments described in the above contents areonly for the present disclosure to be understood easily, not forlimiting the present disclosure. Any person skilled in the art to whichthe present disclosure pertains may make any modifications andvariations in the form and details of implementation without departingfrom the spirit and scope of the present disclosure. Nevertheless, theprotection scope of the present disclosure shall still be determined bythe scope defined by the appended claims.

What we claim is:
 1. A shift register, comprising: an input sub-circuit,a first reset sub-circuit, an output sub-circuit, a pull-downsub-circuit, a pull-down control sub-circuit and a second resetsub-circuit, wherein the input sub-circuit is configured to, undercontrol of a signal input terminal, provide a signal of a first voltagesource to a pull-up node and a first node respectively; the first resetsub-circuit is configured to, under control of a reset terminal, providea signal of a second voltage source to the pull-up node and the firstnode respectively; the output sub-circuit is configured to, according toa level of the pull-up node, output a signal of a clock signal terminalto a signal output terminal; the pull-down control sub-circuit isconfigured to, according to the level of the pull-up node and a signalof a third voltage source, control a level of a pull-down node; thepull-down sub-circuit is configured to, according to a level of thefirst node, output a level of a fourth voltage source to the pull-downnode, and, according to the level of the pull-down node, output thelevel of the fourth voltage source to the pull-up node and the signaloutput terminal; and the second reset sub-circuit is configured to,under control of a total reset terminal, reset the pull-up node and thesignal output terminal.
 2. The shift register according to claim 1,wherein the input sub-circuit comprises: a first transistor and a secondtransistor, a control electrode of the first transistor is connectedwith the signal input terminal, a first electrode of the firsttransistor is connected with the first voltage source, and a secondelectrode of the first transistor is connected with the pull-up node;and a control electrode of second transistor is connected with thesignal input terminal, a first electrode of the second transistor isconnected with the first voltage source, and a second electrode of thesecond transistor is connected with the first node.
 3. The shiftregister according to claim 1, wherein the first reset sub-circuitcomprises: a third transistor and a fourth transistor, a controlelectrode of the third transistor is connected with the reset terminal,a first electrode of the third transistor is connected with the secondvoltage source, and a second electrode of the third transistor isconnected with the pull-up node; and a control electrode of the fourthtransistor is connected with the reset terminal, a first electrode ofthe fourth transistor is connected with the second voltage source, and asecond electrode of the fourth transistor is connected with the firstnode.
 4. The shift register according to claim 1, wherein the pull-downsub-circuit comprises: a fifth transistor, a sixth transistor and aseventh transistor, a control electrode of the fifth transistor isconnected with the first node, a first electrode of the fifth transistoris connected with the fourth voltage source, and a second electrode ofthe fifth transistor is connected with the pull-down node; a controlelectrode of the sixth transistor is connected with the pull-down node,a first electrode of the sixth transistor is connected with the fourthvoltage source, and a second electrode of the sixth transistor isconnected with the pull-up node; and a control electrode of the seventhtransistor is connected with the pull-down node, a first electrode ofthe seventh transistor is connected with the fourth voltage source, anda second electrode of the seventh transistor is connected with thesignal output terminal.
 5. The shift register according to claim 1,wherein the pull-down control sub-circuit comprises: an eighthtransistor, a ninth transistor, a tenth transistor and an eleventhtransistor, a control electrode and a first electrode of the eighthtransistor both are connected with the third voltage source, and asecond electrode of the eighth transistor is connected with a secondnode; a control electrode of the ninth transistor is connected with thesecond node, a first electrode of the ninth transistor is connected withthe third voltage source, and a second electrode of the ninth transistoris connected with the pull-down node; a control electrode of the tenthtransistor is connected with the pull-up node, a first electrode of thetenth transistor is connected with the second node, and a secondelectrode of the tenth transistor is connected with the fourth voltagesource; and a control electrode of the eleventh transistor is connectedwith the pull-up node, a first electrode of the eleventh transistor isconnected with the pull-down node, and a second electrode of theeleventh transistor is connected with the fourth voltage source.
 6. Theshift register according to claim 1, wherein the output sub-circuitcomprises: a twelfth transistor and a capacitor, a control electrode ofthe twelfth transistor is connected with the pull-up node, a firstelectrode of the twelfth transistor is connected with the clock signalterminal, and a second electrode of the twelfth transistor is connectedwith the signal output terminal; and a terminal of the capacitor isconnected with the pull-up node, and the other terminal of the capacitoris connected with the signal output terminal.
 7. The shift registeraccording to claim 1, wherein the second reset sub-circuit comprises: athirteenth transistor and a fourteenth transistor, a control electrodeof the thirteenth transistor is connected with the total reset terminal,a first electrode of the thirteenth transistor is connected with thefourth voltage source, and a second electrode of the thirteenthtransistor is connected with the signal output terminal; and a controlelectrode of the fourteenth transistor is connected with the total resetterminal, a first electrode of the fourteenth transistor is connectedwith the fourth voltage source, and a second electrode of the fourteenthtransistor is connected with the pull-up node.
 8. The shift registeraccording to claim 1, wherein the input sub-circuit comprises: a firsttransistor and a second transistor, the first reset sub-circuitcomprises a third transistor and a fourth transistor, the pull-downsub-circuit comprises a fifth transistor, a sixth transistor, and aseventh transistor, the pull-down control sub-circuit comprises aneighth transistor, a ninth transistor, a tenth transistor and aneleventh transistor, the output sub-circuit includes a twelfthtransistor and a capacitor, and the second reset sub-circuit comprises:a thirteenth transistor and a fourteenth transistor, a control electrodeof the first transistor is connected with the signal input terminal, afirst electrode of the first transistor is connected with the firstvoltage source, and a second electrode of the first transistor isconnected with the pull-up node; a control electrode of secondtransistor is connected with the signal input terminal, a firstelectrode of the second transistor is connected with the first voltagesource, and a second electrode of the second transistor is connectedwith the first node; a control electrode of the third transistor isconnected with the reset terminal, a first electrode of the thirdtransistor is connected with the second voltage source, and a secondelectrode of the third transistor is connected with the pull-up node; acontrol electrode of the fourth transistor is connected with the resetterminal, a first electrode of the fourth transistor is connected withthe second voltage source, and a second electrode of the fourthtransistor is connected with the first node; a control electrode of thefifth transistor is connected with the first node, a first electrode ofthe fifth transistor is connected with the fourth voltage source, and asecond electrode of the fifth transistor is connected with the pull-downnode; a control electrode of the sixth transistor is connected with thepull-down node, a first electrode of the sixth transistor is connectedwith the fourth voltage source, and a second electrode of the sixthtransistor is connected with the pull-up node; and a control electrodeof the seventh transistor is connected with the pull-down node, a firstelectrode of the seventh transistor is connected with the fourth voltagesource, and a second electrode of the seventh transistor is connectedwith the signal output terminal; a control electrode and a firstelectrode of the eighth transistor both are connected with the thirdvoltage source, and a second electrode of the eighth transistor isconnected with a second node; a control electrode of the ninthtransistor is connected with the second node, a first electrode of theninth transistor is connected with the third voltage source, and asecond electrode of the ninth transistor is connected with the pull-downnode; a control electrode of the tenth transistor is connected with thepull-up node, a first electrode of the tenth transistor is connectedwith the second node, and a second electrode of the tenth transistor isconnected with the fourth voltage source; a control electrode of theeleventh transistor is connected with the pull-up node, a firstelectrode of the eleventh transistor is connected with the pull-downnode, and a second electrode of the eleventh transistor is connectedwith the fourth voltage source; a control electrode of the twelfthtransistor is connected with the pull-up node, a first electrode of thetwelfth transistor is connected with the clock signal terminal, and asecond electrode of the twelfth transistor is connected with the signaloutput terminal; a terminal of the capacitor is connected with thepull-up node, and the other terminal of the capacitor is connected withthe signal output terminal; a control electrode of the thirteenthtransistor is connected with the total reset terminal, a first electrodeof the thirteenth transistor is connected with the fourth voltagesource, and a second electrode of the thirteenth transistor is connectedwith the signal output terminal; and a control electrode of thefourteenth transistor is connected with the total reset terminal, afirst electrode of the fourteenth transistor is connected with thefourth voltage source, and a second electrode of the fourteenthtransistor is connected with the pull-up node.
 9. A gate drivingcircuit, comprising a plurality of cascaded shift registers according toclaim
 1. 10. A driving method for a shift register, applied to the shiftregister according to claim 1, wherein during a forward scan, thedriving method comprises: providing, by the input sub-circuit, under thecontrol of the signal input terminal, the signal of the first voltagesource to the pull-up node and the first node; pulling down, by thepull-down control sub-circuit, according to the level of the pull-upnode, the level of the pull-down node; outputting, by the pull-downsub-circuit, according to the level of the first node, the level of thefourth voltage source to the pull-down node; outputting, by the outputsub-circuit, according to the level of the pull-up node, the signal ofthe clock signal terminal to the signal output terminal; and providing,by the first reset sub-circuit, under the control of the reset terminal,the signal of the second voltage source to the pull-up node and thefirst node respectively; pulling up, by the pull-down controlsub-circuit, according to the signal of the third voltage source, thelevel of the pull-down node; outputting, by the pull-down sub-circuit,according to the level of the pull-down node, the level of the fourthvoltage source to the pull-up node and the signal output terminal. 11.The driving method according to claim 10, wherein during a reverse scan,the driving method comprises: providing, by the first reset sub-circuit,under the control of the reset terminal, the signal of the secondvoltage source to the pull-up node and the first node respectively;pulling down, by the pull-down control sub-circuit, according to thelevel of the pull-up node, the level of the pull-down node; outputting,by the pull-down sub-circuit, according to the level of the first node,the level of the fourth voltage source to the pull-down node;outputting, by the output sub-circuit, according to the level of thepull-up node, the signal of the clock signal terminal to the signaloutput terminal; and providing, by the input sub-circuit, under thecontrol of the signal input terminal, the signal of the first voltagesource to the pull-up node and the first node respectively; pulling up,by the pull-down control sub-circuit, according to the signal of thethird voltage source, the level of the pull-down node; outputting, bythe pull-down sub-circuit, according to the level of the pull-down node,the level of the fourth voltage source to the pull-up node and thesignal output terminal.